Conventionally, relatively soft metals such as zinc and zinc alloys, particularly alloys with aluminum and/or magnesium, are used for plastic injection molds only when small numbers of prototypes are desired and/or when quality is not critical for the initial study of a prototype. Where larger numbers of the molded piece or article are needed, say, more than one hundred, and/or where quality is necessary even for a few prototypes, the molds are typically made from steel at much higher cost because of the skilled labor, time and material required.
The art is in need of a method of quickly making relatively inexpensive molds capable of making large runs of thermoplastic pieces, i.e. more than 100 and frequently many more than 100.